Some new projection televisions include a light engine. Such light engines use a piezo-electric actuator and a rocking mechanism to hit a smoothing mirror between two locations. One example of the smooth picture actuator is a spring-mass type system. The piezo-electric actuator is designed to multiplex a video image that is decomposed into two sub-images. When sub-image A is projected on the screen, a small mirror ˜25 mm×25 mm is held in position “A”. Microseconds later, when sub-image B is projected, the piezo-electric motor is actuated and moves the rocker arm that the mirror is attached to into position “B”. When the next sub-image “A” is projected, current is removed form the piezo device and a return spring, for example, moves the mirror and rocker arm back into position “A”.
In the presence of audible noise from speakers or shock waves that can be transmitted by someone walking across a floor, there can be transmission of these forces into the light engine and into the piezo-electric actuator device. It is not uncommon for the amplitude of these forces to be amplified as they are transmitted through the system of the television cabinet plastics and light engine. When these forces are transmitted to the piezo-electric actuator device they may be large enough to undesirably induce motion in the rocker arm that overcomes the spring force and allows the mirror to oscillate outside of its intended frequency